X2 - TransGo works very well.
With the turbo you may need to add some hard parts or it will give up.
The choice of converter stall depends on:
1. idle quality required (stall too low - it dies when you drop it in drive)
2. how hot is the cam?
3. are you traction limited?
3,000 stall will definitely feel good, but may be un-driveable in the rain, and slow up your 60 foot time (with street tires and suspension tune).
Are you going to keep converter lock-up? A converter that will stay locked with 500 ft. lbs. is $$$.